I had the exact same issue here
http://bit.ly/nIcmyd
After upgrading to 1.5
the update crashed my site, and presented a blank page, where I could not log into the admin consule.
Thank god I used the plugin EZPZ Backup to restore
However, after restoring, The activity Stream here, http://bit.ly/nIcmyd, is not working
Activity is not being displayed and the entire right side is missing widgets and formatting.
Any ideas’ on how to fix this and resolve it?
I tried contacting Studiopress but they wanted me to purchase a product that did not Guarantee a resolution
Thanks